Greylings are a small but incredibly fast breed of dragon. They are often used as couriers and lookouts. They can stay aloft for long periods of time, which makes them ideal for delivering mail. James boasted that Volly could stay in the air for an hour only beating his wings once and that the two of them had made 14-hour flights.

Greylings appear to have been used especially on the longer courier routes, from Britain to India, Africa and the Americas, while the more common Winchesters were used for the shorter routes.

Greylings were created by British breeds by crossing the even-tempered Winchesters with Grey Widowmakers, a small and aggressive breed of dragons that is mostly extinct.